Add.
Explanation: There are many ways to solve this problem. Let's see two ways we can solve it. Place value table Let's line up the numbers by their decimal places. Ones $.$ Tenths ${4}$ $.$ ${0}$ $5$ $.$ ${7}$ Because $4$ is a whole number, we can add a decimal point and a $0$ behind to make the columns align. Now, let's add each place value column. Ones $.$ Tenths ${4}$ $.$ ${0}$ $+$ ${5}$ $.$ ${7}$ $\underline{~~~~}$ $\underline{~~~~}$ $\underline{~~~~}$ $9$ $.$ $7$ Decomposing the numbers We can group the whole numbers together and the decimals together. $\begin{aligned} &(4 + 5) + {0.7}\\\\ &=9 + {0.7}\\\\ &=9.7 \end{aligned}$ $9.7 = 4 + 5.7$